1. Field of the Invention
This invention relates to new and useful improvements in electrosurgical instruments and more particularly to an instrument having an electro-cauterizing blade and provision for selective application of vacuum to the surgical site.
2. Brief Description of the Prior Art
Electrosurgical instruments having an electric cauterizing blade and some means for aspirating blood and/or smoke from the surgical area have been disclosed in the literature for about 50 years.
Hyams U.S. Pat. No. 2,102,270 discloses an electrosurgical instrument for female sterilization procedures having an auxiliary tube surrounding the electric blade for introduction of a liquid for radiologically monitoring the operation.
Bierman U.S. Pat. No. 2,275,167 discloses an electrosurgical instrument for removal of tissue by electric current and having means for applying vacuum for drawing in and holding the tissue being cut.
August U.S. Pat. No. 2,808,833 discloses an electro-cauterizing instrument with a tube for supplying an inert gas to blanket the surgical site.
Seiger U.S. Pat. No. 2,888,928 discloses an electro-cauterizing instrument with a tube for withdrawing blood and smoke from the surgical site by vacuum.
Morrison U.S. Pat. No. 3,828,780 discloses an electro-cauterizing instrument with a tube for withdrawing blood and smoke from the surgical site by vacuum and having a side vent opening.
Roberts U.S. Pat. No. 3,906,955 discloses an electro-cauterizing instrument with a tube for withdrawing blood and smoke from the surgical site by vacuum and constructed for easy replacement of the blade.
Durden U.S. Pat. No. 3,974,833 discloses an electro-cauterizing instrument with a tube for withdrawing blood and smoke from the surgical site by vacuum and having a side vent opening arranged for selective opening and closing to control application of vacuum.
Walker U.S. Pat. No. 4,562,838 discloses an electro-cauterizing instrument with a tube for supplying fluid to the surgical site for removing blood and smoke and having a light transmitting cable for illuminating the surgical site.
The prior art as exemplified by these patents and by the instruments now in use in surgery have certain similarities and certain deficiencies in design. All instruments of this type have an electrode for high frequency electro-coagulation. Likewise, most instruments of this type have a tube associated with the blade to either supply a liquid to the surgical site or to aspirate blood and fluid or air (smoke) away from the site. Roberts U.S. Pat. No. 3,906,955 and Walker U.S. Pat. No. 4,562,838 have superficial similarities to my invention and in certain applications work similarly. However these instruments are not as versatile and do not work well in all types of operating conditions. Roberts U.S. Pat. No. 3,906,955 discloses an electro-cauterizing instrument with a tube for withdrawing blood and smoke from the surgical site by vacuum but has a design which provides an inadequate air circulation through the tip for removal of smoke and fluids. Walker U.S. Pat. No. 4,562,838 discloses an electro-cauterizing instrument with a tube for supplying fluid to the surgical site for removing blood and smoke and having a light transmitting cable for illuminating the surgical site, but has an inefficient design of the air flow passages for removal of blood and smoke from the surgical site.